Low-carbon deep-desulfurization refining method of LF (ladle refining) furnace

Abstract

The invention discloses a low-carbon deep-desulfurization refining method of an LF (ladle refining) furnace, which comprises the following steps of: 1) heating and slagging; 2) power-off forced stirring and deep desulfurization; 3) slag regulation and component adjustment; 4) secondary power-off forced stirring and deep desulfurization; and 5) power transmission temperature regulation. According to the method disclosed by the invention, by optimizing a whole-course argon blowing gas supply model of the LF furnace and dynamically controlling the argon flow in stages, enough argon blowing stirring work is provided to guarantee the desulfurization effect, and violent rolling of steel and slag caused by excessive argon flow in a heating process and consequent contact reaction between steel, slag and graphite electrodes leading to recarburization are avoided; by adopting an intermittent heating mode of alternate power supply and power cut and reallocating the tasks in the power supply period and power-cut period, the stirring intensity is reduced by reducing the argon flow in the power supply period, and recarburization is reduced during desulfurization; and meanwhile, the stirring is enhanced by increasing the argon flow in the power-cut period to finish deep desulfurization. Thus, the deep desulfurization is finished while effectively controlling the recarburization in the whole refining process.

Description

Technical field [0001] The invention relates to the technical field of steelmaking, in particular to a low-carbon deep desulfurization refining method for an LF furnace. Background technique [0002] LF furnace (ie ladle refining furnace) is the main external refining equipment in steel production. Its main tasks are: desulfurization, temperature adjustment, precise composition fine-tuning, improvement of molten steel purity, and slagging. Among them, the LF furnace refining mainly relies on the white slag in the barrel to desulfurize the molten steel in a low-oxygen reducing atmosphere. At the same time, the argon blowing device is used to blow argon into the barrel for stirring to accelerate the gap between the white slag and the molten steel. In order to ensure sufficient refining time, the graphite electrode will heat the molten steel through the primary furnace for temperature compensation. [0003] At present, deep desulfurization technologies mainly include deep desulfuriza...

AI Technical Summary

Problems solved by technology

Therefore, in the actual production of low-carbon and ultra-low-sulfur steel, it often occurs that the carbon content is too high due to operational factors such as improper control of argon blowing at the bottom of the LF furnace, and the RH furnace is forced to use the oxygen blowing decarburization mode to save the composition, so that Detrimental effects on molten steel quality and production efficiency

[0008] At present, there are some studies on the deep desulfurization refining process of LF furnace at home and abroad, such as: the Chinese patent application with the publication number CN102002554A and the publication date being April 6, 2011, which adopts powder spraying metallurgy to desulfurize and achieves a better Desulfurization effect, but the sulfur content at the end of the treatment is unstable, and powder spraying metallurgy increases equipment investment; the publication number is JP6145764A, and the publication date is a Japanese patent application on May 27, 1994, which mainly focuses on the research and development of refining slag systems. The reuse of refining slag is obviously different from the method of the present invention

However, there is no relevant report on how to achieve ultra-deep desulfurization while effectively controlling carbon increase in LF furnaces, which is still a technical blank

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